The PCM has the ability to increase and decrease the amount of fuel to each cylinder in order to provide for a smooth idle operation. If the fuel correction amount exceeds the define limits, DTC P0263 will set.
• | The engine is at idle. |
• | The engine coolant is at the normal temperatures. |
• | The cylinder fault must be constant. |
• | The fuel correction amount exceeds the limits (internal to PCM). |
• | The conditions were met for 2 seconds. |
• | The PCM will not illuminate the Malfunction Indicator Lamp (MIL). |
• | The PCM records the operating conditions at the time the diagnostic fails. This information stores in the Failure Records. |
• | A History DTC will clear after forty consecutive warm-up cycles during which the diagnostic does not fail (the coolant temperature has risen 5°C (40°F) from the start up coolant temperature and the engine coolant temperature exceeds 71°C (160°F) during that same ignition cycle). |
• | Use of a Scan tool will clear the DTC codes. |
The injector balance test on the scan tool should be used in order to confirm the cylinder problems. The Scan Tool will cutout the specific cylinder requested. If the original complaint was multiple cylinder balance DTCs and the vehicle has a manual transmission, a dual mass flywheel could be at fault. If a cylinder balance fault has been detected and the engine has been running for a long time, the PCM might try to increase or decrease the fuel in the other cylinders in order to compensate for a rough idle which may cause multiple cylinder balance DTCs to set. The scan tool snap shot mode can be used to properly identify the suspected cylinder. The most likely cause of cylinder balance DTCs are malfunctioning nozzles or any engine mechanical (low compression) problems.
The numbers below refer to the step numbers on the Diagnostic Table.
Step | Action | Value(s) | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|---|
1 |
Important: Before clearing any DTCs, use the Scan Tool Capture Info to save freeze frame and failure records for reference, as the Scan Tool loses data when using the Clear Info function. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to A Powertrain On Board Diagnostic (OBD) System Check | |||||||
Is there an RPM drop in the suspected cylinder? | -- | |||||||||
3 | The DTC is intermittent.
Are there any additional DTCs stored? | -- | Go to the applicable DTC table | Go to Diagnostic Aids | ||||||
4 |
Was a repair performed? | -- | ||||||||
5 | Replace the fuel injection pump. Refer to Fuel Injection Pump Replacement . Important: The new injection pump must be timed. Refer to Injection Timing Adjustment . Is the action complete? | -- | -- | |||||||
6 |
Does the Scan Tool indicate the diagnostic Passed? | -- | ||||||||
7 | Does the Scan Tool display any additional undiagnosed DTCs? | -- | Go to the applicable DTC table | System OK |